An electronic device such as an acoustic wave device that functions as a filter or a duplexer, for example, is mounted in a communication device such as a cellular phone. The function part of the acoustic wave device excites acoustic waves and is therefore exposed to an opening. Japanese Patent Application Publication No. 2008-546207 discloses a technique in which two substrates are bonded together so as to form a gap therebetween and a device structure is provided in the gap.
A module mounted in a communication device such as a cellular phone includes an acoustic wave device that functions as a filter or a duplexer, for example. Japanese Patent Application Publication No. 2013-132014 discloses an arrangement in which a filter chip is buried in a substrate. This arrangement improves the degree of integration and enables downsizing of the module.
Terminals for inputting and outputting signals to and from the function part are provided on a single main surface of a substrate. However, the distances between the adjacent terminals on the single surface of the electronic device are small, and therefore, interference may occur therebetween. The interference deteriorates the electrical performance of the electronic device.
On a substrate, there are provided interconnections that connect terminals of an acoustic wave device built in the substrate and terminals on the substrate together. If the terminals are provided on only one of the opposite surfaces of the acoustic wave device, the interconnections are caused to bypass the acoustic wave device. However, the routing of the interconnections around the acoustic wave device increases the area occupied by the interconnections and decreases the design flexibility.